Alpinia galanga (L.), family Zingiberaceae, commonly known as Greater Galangal or Java Galangal, is cultivated and grows wild in Asia. The herb is rhizomatic, 1.8-2.1 m in height with oblong glabrous leaves and greenish white flowers. The fruits are orange-red capsules. The plant is also known under the name Languas galanga, especially in Thailand, and here it is locally called Katuk karohinee. 
In relation to the present invention the term “Alpinia galanga” refers to any variety of Alpinia galanga or Languas galanga found anywhere in the world.
The volatile oil of Alpinia galanga can be obtained by steam distillation of the rhizome. It consists primarily of terpenoids with 1,8-cineol as the most abundant compound. Other major terpenoids are: α-pinene, β-pinene, limonene, α-terpineol, terpene-4-ol, and trans-β-farnesene.
Another important class of chemicals in Alpinia galanga are aromatic compounds. The quantitatively dominating compound of this class is 1′-acetoxychavicol acetate. Other aromatic constituents are: 1′-acetoxyeugenol acetate, trans-p-coumaryl diacetate, coniferyl diacetate, 1′-hydroxychavicol acetate, 1′-hydroxychavicol, p-hydroxy-trans-cinnamaldehyde, p-methoxy-trans-cinnamylalcohol and 3,4-dimethoxy-trans-cinnamylalcohol.
Among the components of Alpinia galanga several have been shown to exert pharmacological actions. Thus, Janssen and Scheffer found that 1′-acetoxychavicol acetate is anti-fungal (Janssen, A. M. and Scheffer, J. J. C., Planta Medica, pp. 507-511, 1985). Furthermore Watanabe et al found that 1′-acetoxychavicol acetate inhibits phagocytosis of peritoneal macrophages (Watanabe, N. et al, Biosci., Biotechnol., Biochem., vol 59 (8), pp 1566-67, 1995).
Extracts or concentrates of Alpinia galanga containing synergistic compositions of terpenoids and aromatic compounds have not previously been described.
Hypersensitivity is defined as a state of altered reactivity in which the body reacts with, an exaggrated immune response to a substance (antigen). Hypersensitivity may be caused by exogenous or endogenous antigens.
Hypersensitivity reactions underlie a large number of diseases. Amongst these allergic and autoimmune conditions are of great importance. A classification of hypersensitivity diseases is given by Parveen Kumar and Michael Clark in the textbook “Clinical Medicine” (3rd edition, 1994, pp. 147-150, Baillière Tindall, London).
Type I hypersensitivity reactions (IgE mediated allergic reactions) are caused by allergens (specific exogenous antigens), e.g. pollen, house dust, animal dandruff, moulds, etc. Allergic diseases in which type I reactions play a significant role include asthma, eczema (atopic dermatitis), urticaria, allergic rhinitis and anaphylaxis.
Type II hypersensitivity reactions are caused by cell surface or tissue bound antibodies (IgG and IgM) and play a significant role in the pathogenesis of myasthenia gravis, Goodpasture's syndrome and Addisonian pernicious anaemia.
Type III hypersensitivity reactions (immune complex) are caused by autoantigens or exogenous antigens, such as certain bacteria, fungi and parasites. Diseases in which type III hypersensitivity reactions play a significant role include lupus erythematosus, rheumatoid arthritis and glomerulonephritis.
Type IV hypersensitivity reactions (delayed) are caused by cell or tissue bound antigens. This type of hypersensitivity plays a significant role in a number of conditions, e.g. graft-versus-host disease, leprosy, contact dermatitis and reactions due to insect bites.
A number of drug classes are available for the treatment of hypersensitivity reactions. Some of these are systemic and some are applied topically.
The corticosteroids are among the most widely used drugs for the treatment of hypersensitivity diseases. Corticosteroids primarily exert their pharmacological action by non-selectivity inhibiting the function and proliferation of different classes of immune cells. Hereby hypersensitivity reaction are suppressed. Unfortunately the corticosteroids are associated with a number of serious side effects e.g. immunosuppression, osteoporosis and skin atrophy (when applied topically).